U.S. patent application number 15/241476 was filed with the patent office on 2017-06-08 for power switch capable of preventing reverse connection.
The applicant listed for this patent is Hyundai Motor Company, Industry-Academic Cooperation Foundation, Dankook University, Kia Motors Corporation. Invention is credited to Sang Hyun Jang, Jun Sik Kim, Sun Woo Kim, Hee Jun Lee, Jae Hyun Park, Shi Hong Park.
Application Number | 20170163033 15/241476 |
Document ID | / |
Family ID | 58799879 |
Filed Date | 2017-06-08 |
United States Patent
Application |
20170163033 |
Kind Code |
A1 |
Jang; Sang Hyun ; et
al. |
June 8, 2017 |
POWER SWITCH CAPABLE OF PREVENTING REVERSE CONNECTION
Abstract
A power switch capable of preventing a reverse connection is
provided. The power switch includes a switch that is configured to
supply power of a battery to a load or block the power of the
battery and a protector that is connected to an output terminal of
the switch and blocks the power applied from the battery when the
battery is reversely connected and a driver is configured to
operate a driving of the switch and the protector.
Inventors: |
Jang; Sang Hyun; (Yongin,
KR) ; Kim; Sun Woo; (Seoul, KR) ; Lee; Hee
Jun; (Seoul, KR) ; Park; Shi Hong; (Seoul,
KR) ; Kim; Jun Sik; (Chungcheongbuk-do, KR) ;
Park; Jae Hyun; (Anyang, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company
Kia Motors Corporation
Industry-Academic Cooperation Foundation, Dankook
University |
Seoul
Seoul
Yongin |
|
KR
KR
KR |
|
|
Family ID: |
58799879 |
Appl. No.: |
15/241476 |
Filed: |
August 19, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H03K 2217/0009 20130101;
H02H 1/0007 20130101; H03K 17/08122 20130101; H03K 2217/0027
20130101; H02H 11/003 20130101 |
International
Class: |
H02H 11/00 20060101
H02H011/00; H02H 1/00 20060101 H02H001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2015 |
KR |
10-2015-0171721 |
Claims
1. A power switch that prevents a reverse connection, the power
switch comprising: a switch configured to supply power of a battery
to a load or block the power of the battery; a protector coupled to
an output terminal of the switch and configured to block the power
applied from the battery when the battery is reversely connected;
and a driver configured to adjust a driving of the switch and the
protector.
2. The power switch according to claim 1, wherein the switch is an
internal high voltage field effect transistor (FET).
3. The power switch according to claim 2, wherein the high voltage
FET has a n-type double-diffused metal oxide semiconductor (DMOS)
structure.
4. The power switch according to claim 2, wherein the protector
includes: a first FET configured to measure a current, and a second
FET configured to block the current supplied from the battery by a
parasitic diode when the battery is reversely connected.
5. The power switch according to claim 4, wherein gate terminals of
the first FET and the second FET are coupled to an output terminal
of the driver and source terminals of the first FET and the second
FET are coupled to a source terminal of the high voltage FET.
6. The power switch according to claim 4, wherein the first FET and
the second FET are an internal low voltage FET.
7. The power switch according to claim 6, wherein the low voltage
FET has an n-type complementary metal-oxide semiconductor (CMOS)
structure.
8. The power switch according to claim 4, further comprising a
sensor coupled to a drain terminal of the first FET and configured
to sense a load current
9. The power switch according to claim 8, wherein the first FET and
the second FET are configured to transfer a current output from the
switch at a ratio of 1:N.
10. The power switch according to claim 8, wherein the protector is
formed by the same process as the sensor and the driver.
11. The power switch according to claim 8, wherein the driver is
configured to operate a load driving based on a controller
positioned on the exterior of the power switch.
12. The power switch according to claim 11, wherein the controller
is configured to measure the load current using an external
resistor connected in series with an output terminal of the sensor
and configured to operate the driver based on the measured load
current.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims the benefit of
priority to Korean Patent Application No. 10-2015-0171721, filed on
Dec. 3, 2015 in the Korean Intellectual Property Office, the
disclosure of which is incorporated herein in its entirety by
reference.
BACKGROUND
[0002] Technical Field
[0003] The present disclosure relates to a power switch and more
particularly to a power switch capable of preventing a reverse
connection that blocks a current supplied from a battery when the
battery is reversely connected.
[0004] Description of the Related Art
[0005] Generally, a switch for a vehicle is replaced with a power
switch having high stability and reliability and absent mechanical
noise from an existing relay type. However, since an intelligent
power switch (e.g., a sense field effect transistor (FET))
according to the related art has a high current sensing error rate,
implementation within a protection circuit is difficult. Further,
unlike a relay switch, the intelligent power switch according to
the related art does not block a current supplied from the battery
when the battery is reversely connected, due to an internal
parasitic diode (e.g., a body diode). Accordingly, an additional
external protection element that prevents the above-mentioned
problem is demanded for each of controllers.
[0006] The above information disclosed in this section is intended
merely to aid in the understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY
[0007] An aspect of the present disclosure provides a power switch
capable of preventing a reverse connection that blocks a current
supplied from a battery when the battery is reversely
connected.
[0008] According to an exemplary embodiment of the present
disclosure, a power switch capable of preventing a reverse
connection may include a switch configured to supply power of a
battery to a load or block the power of the battery, a protector
coupled to an output terminal of the switch and configured to block
the power applied from the battery when the battery is reversely
connected and a driver configured to execute a driving of the
switch and the protector.
[0009] The switch may be implemented as an internal high voltage
field effect transistor (FET). The high voltage FET may have a
n-type double-diffused metal oxide semiconductor (DMOS) structure.
The protector may include a first FET configured to measure a
current and a second FET configured to block the current supplied
from the battery by a parasitic diode when the battery is reversely
connected. Gate terminals of the first FET and the second FET may
be coupled to an output terminal of the driver and source terminals
thereof may be connected to a source terminal of the high voltage
FET. The first FET and the second FET may be implemented as an
internal low voltage FET. The low voltage FET may have an n-type
complementary metal-oxide semiconductor (CMOS) structure.
[0010] The power switch may further include a sensor coupled to a
drain terminal of the first FET and configured to sense a load
current. The first FET and the second FET may be configured to
transfer a current output from the switch at a ratio of 1:N. The
protector may be formed by the same process as the sensor and the
driver. The driver may be configured to execute a load driving
based on a controller positioned external to the power switch. The
controller may be configured to measure the load current using an
external resistor connected in series with an output terminal of
the sensor and may be configured to operate the driver based on the
measured load current.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above and other objects, features and advantages of the
present disclosure will be more apparent from the following
detailed description when taken in conjunction with the
accompanying drawings.
[0012] FIG. 1 is an exemplary circuit diagram illustrating a power
switch capable of preventing a reverse connection according to an
exemplary embodiment of the present disclosure;
[0013] FIG. 2 is an exemplary diagram illustrating a structure of a
low voltage field effect transistor (FET) according to an exemplary
embodiment of the present disclosure;
[0014] FIG. 3 is an exemplary diagram illustrating an off operation
of the power switch according to an exemplary embodiment of the
present disclosure;
[0015] FIG. 4 is an exemplary diagram illustrating an on operation
of the power switch according to an exemplary embodiment of the
present disclosure; and
[0016] FIG. 5 is an exemplary diagram illustrating an operation of
the power switch when a battery is reversely connected, according
to an exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
[0017] Hereinafter, exemplary embodiments of the present disclosure
will be described in detail with reference to the accompanying
drawings. It is to be noted that in giving reference numerals to
components of each of the accompanying drawings, the same
components will be denoted by the same reference numerals even
though they are shown in different drawings. Further, in describing
exemplary embodiments of the present disclosure, well-known
constructions or functions will not be described in detail in the
case in which they may unnecessarily obscure the understanding of
the exemplary embodiments of the present disclosure.
[0018] The terminology used herein is for the purpose of describing
particular exemplary embodiments only and is not intended to be
limiting of the disclosure. As used herein, the singular forms "a",
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof. As used herein, the term "and/or" includes any and
all combinations of one or more of the associated listed items. For
example, in order to make the description of the present invention
clear, unrelated parts are not shown and, the thicknesses of layers
and regions are exaggerated for clarity. Further, when it is stated
that a layer is "on" another layer or substrate, the layer may be
directly on another layer or substrate or a third layer may be
disposed therebetween.
[0019] Unless specifically stated or obvious from context, as used
herein, the term "about" is understood as within a range of normal
tolerance in the art, for example within 2 standard deviations of
the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%,
5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated
value. Unless otherwise clear from the context, all numerical
values provided herein are modified by the term "about".
[0020] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicle in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats, ships, aircraft, and the
like and includes hybrid vehicles, electric vehicles, combustion,
plug-in hybrid electric vehicles, hydrogen-powered vehicles and
other alternative fuel vehicles (e.g. fuels derived from resources
other than petroleum).
[0021] The present disclosure relates to a power switch for a
vehicle, and may improve current sensing error via a low voltage
field effect transistor (FET) and may protect the power switch by
blocking a current when a power source is reversely connected.
[0022] FIG. 1 is an exemplary circuit diagram illustrating a power
switch capable of preventing a reverse connection according to an
exemplary embodiment of the present disclosure. FIG. 2 illustrates
a structure of a low voltage field effect transistor (FET)
according to an exemplary embodiment of the present disclosure. As
illustrated in FIG. 1, a power switch 100 may be disposed between a
battery (not illustrated) and a load A, and may be configured to
operate under a control of a controller 200. The power switch 100
may be configured to supply (e.g., transfers) power V.sub.BAT of
the battery to the load A or may be configured to block the
V.sub.BAT of the battery. For example, the load A may be an
electric motor, an actuator, and the like. The power switch 100 may
include a driver 110, a sensor 120, a switch 130, and a protector
140. The driver 110 may be configured to operate the switch 130 and
the protector 140 based on a control command output from the
controller 200. The driver 110 may be configured to drive the
switch 130 and the protector 140. The sensor 120 may be configured
to measure a load current. The sensor 120 may be configured to
output the sensed current to the driver 110 and the exterior.
[0023] The switch 130 may be engaged or disengaged (e.g., turned on
or off) based on an output (e.g., a control signal) of the driver
110 and may be configured to supply the power V.sub.BAT of the
battery to the load A or may be configured to block the power
V.sub.BAT of the battery. In other words, the switch 130 may be
configured to adjust a driving of the load A. The switch 130 may be
an internal high voltage field effect transistor (FET). A gate
terminal of the high voltage FET 130 may be connected to an output
terminal of the driver 110, and a drain terminal thereof may be
connected to the power V.sub.BAT of the battery. The high voltage
FET 130 may include a n-type (e.g., n-channel) double-diffused
metal oxide semiconductor (DMOS) structure. Further, the high
voltage FET 130 may include a round-shaped horizontal
cross-sectional structure.
[0024] The protector 140 may be configured to perform a reverse
connection protection function that blocks power applied to the
power switch 100 when the battery is reversely connected, and a
current sensing function that measures the load current supplied to
the load A through the power switch 100. The protector 140 may be
configured of a first FET M1 and a second FET M2 coupled in
parallel to each other and have a current transfer ratio of 1:N.
For example, N may be predetermined through an experiment, or the
like.
[0025] Gate terminals of the first FET M1 and the second FET M2 may
be connected to the output terminal of the driver 110, and source
terminals thereof may be connected to a source terminal of the
switch 130. In particular, the gate terminals of the first FET M1
and the second FET M2 may receive the same control signal as a gate
terminal of the switch 130. A drain terminal of the first FET M1
may be coupled to an input terminal of the sensor 120, and a drain
terminal of the second FET M2 may be coupled to the load A.
[0026] The first FET M1 and the second FET M2, may be an internal
low voltage FET, and may include an n-type (e.g., n-channel)
complementary metal-oxide semiconductor (CMOS) structure, as
illustrated in FIG. 2. Since the FET having the CMOS structure may
have a minimal withstand voltage, the FET may have a reduced size
and a high matching degree of the element. Further, the FET having
the CMOS structure may have turn on resistance per a unit area less
than the DMOS. Therefore, power loss that may occur by the low
voltage FETs which are connected in series with each other may be
designed by a resistance value less than a scheme in which an
external element may be added to prevent a reverse current (e.g.,
reverse connection). A parasitic diode (e.g., a body diode) D of
the second FET M2 may serve to block the power of the battery when
the battery (not illustrated) is reversely connected. In other
words, the parasitic diode D of the second FET M2 may prevent the
reverse connection of the battery to protect the power switch 100
from the reverse current that may occur when the battery is
reversely connected. Since the driver 100, the sensor 120 and the
protector 140 configuring the above-mentioned power switch 100 may
be formed by the same process, current sensing error by the sensor
120 may be improved.
[0027] When the high voltage FET 130, the first FET M1, and the
second FET M2 are turned on and the load A is driven, the sensor
120 may be configured to sense the load current using the first FET
M1. The sensor 120 may be configured to measure 1/N of a current
that passes through the second FET M2 using the first FET M1. In
other words, the first FET M1 and the second FET M2 may be
configured to distribute a current output from an output terminal
of the switch 130 at a ratio of 1:N and transfer the distributed
current.
[0028] A current sensing scheme using a sense FET based on to the
related art is influenced by deviation due to structural
characteristics of a laterally diffused metal oxide semiconductor
(LDMOS) of a round type. Further, process and temperature
deviations occur since the sensor 120 and the protector 140 use
different MOSs. Therefore, the current sensing scheme using the
sense FET based on the related art configures a current sensing
circuit by adding a circuit that corrects the deviation due to
structural characteristics of the LDMOS of the round type and the
process and temperature deviations. However, since a semiconductor
for a vehicle has a wide dynamic range, the correction circuit
needs to be applied to the entirety of range to improve error.
Since the above-mentioned scheme applies a variety of correction
levels based on the temperature and the load current, the error is
necessarily very large.
[0029] According to the present disclosure, an internal low voltage
FET having the CMOS structure having the small process design
deviation may be configured to sense the current, a problem such as
that in the LDMOS does not occur. Accordingly the current may be
determined without an additional correction circuit. Therefore,
according to the present disclosure, a structure of a system may be
simplified and the current sensing error may be reduced.
[0030] The controller 200 may be configured to operate the power
switch 100 based on a current Is sensed by the sensor 120 of the
power switch 100. In particular, the controller 200 may be
configured to detect a voltage V.sub.R applied to an external
resistor R connected in series with the output terminal of the
sensor 120. The controller 200 may be configured to calculate the
sensed current Is using the detected voltage and a resistance value
of the external resistor R. The controller 200 may be configured to
measure the load current using the external resistor R, and may be
configured to turn on or off of the power switch 100 based on the
measured load current to control the driving of the load A. When
the sensor 120 of the power switch 100 detects an over-current, the
controller 200 may be configured to turn off the power switch 100
to block the over-current from being transferred to the load A. The
above-mentioned controller 200 may be implemented as a micro
controller unit (MCU), a central processing unit (CPU), or the
like.
[0031] FIG. 3 is an exemplary diagram illustrating an off operation
of the power switch according to an exemplary embodiment of the
present disclosure. The controller 200 may be configured to
instruct the load A to terminate the driving thereof, the driver
110 may be configured to terminate the operation of the switch 130
and the protector 140 based on the controller 200. In other words,
the driver 110 may be configured to input an off signal to the gate
terminals of the high voltage FET 130, the first FET M1,and the
second FET M2. Since the parasitic diode D of the second FET M2 may
be formed forwardly with the voltage V.sub.BAT of the battery when
the high voltage FET 130, the first FET M1, and the second FET M2
are in an off state, a forward voltage V.sub.D of the parasitic
diode D may be applied to the second FET M2, and a substantial
amount of the voltage V.sub.BAT of the battery may be applied to
the high voltage FET 130.
[0032] The voltage V.sub.BAT of the battery of tens of voltages V
or more may occur due to a spark voltage that may occur at the time
of turn on or off, due to a load dump that may occur in the vehicle
or characteristics of a coil in a motor, and a substantial portion
of the voltage V.sub.BAT may be applied to the high voltage FET
130. A voltage V.sub.GS between the gate terminal and the source
terminal of the high voltage FET 130, the first FET M1, and the
second FET M2, a voltage V.sub.DS.high voltage between the drain
terminal and the source terminal of the high voltage FET 130, and a
voltage V.sub.DS.low voltage between the drain terminal and the
source terminal of the first FET M1 and the second FET M2 are as
follow.
V.sub.GS=0V
V.sub.DS.highvoltage=V.sub.BAT-V.sub.D
V.sub.DS.lowvoltage=V.sub.D(0.7V)
[0033] FIG. 4 is an exemplary diagram illustrating an on operation
of the power switch according to an exemplary embodiment of the
present disclosure. When the controller 200 instructs the load A to
be driven, the driver 110 may be configured to operate the switch
130 and the protector 140 based on operation of the controller 200.
In other words, the driver 110 may be configured to input an on
signal to the gate terminals of the high voltage FET 130, the first
FET M1, and the second FET M2. Since the driver 110 and the sensor
120 maintain an on state thereof when the high voltage FET 130, the
first FET M1, and the second FET M2 are in an on state, and
substantial portion of the voltage V.sub.BAT of the battery may be
applied across the load A when the high voltage FET 130, the first
FET M1, and the second FET M2 are turned on, a problem does not
occur in the first FET M1 and the second FET M2. In particular, the
voltage V.sub.GS between the gate terminal and the source terminal
of the high voltage FET 130, the first FET M1, and the second FET
M2, the voltage V.sub.DS.high voltage between the drain terminal
and the source terminal of the high voltage FET 130, and the
voltage V.sub.DS.low voltage between the drain terminal and the
source terminal of the first FET M1 and the second FET M2 are as
follow.
V.sub.GS=V.sub.BAT+12V
V.sub.DS.highvoltage=I.sub.O.times.R.sub.DS.ON.highvoltage
V.sub.DS.lowvoltage=I.sub.O.times.R.sub.DS.ON.lowvoltage
[0034] For example, R.sub.DS.ON.high voltage may include a
resistance value between the drain terminal and the source terminal
of the high voltage FET 130 when the high voltage FET 130 is turned
on, and R.sub.DS.ON.low voltage may include a resistance value
between the drain terminal and the source terminal of the first FET
M1 and the second FET M2 when the first FET M1 and the second FET
M2 are turned on.
[0035] FIG. 5 is an exemplary diagram illustrating an operation of
the power switch when a battery is reversely connected, according
to an exemplary embodiment of the present disclosure. As
illustrated in FIG. 5, when a power source of the battery is
reversely connected, the power is not applied to the driver 110,
the output does not occur. Accordingly, the high voltage FET 130,
the first FET M1, and the second FET M2 maintain the off state. In
other words, since the parasitic diode of the second FET M2 may be
backwardly connected to the voltage V.sub.BAT of the battery
reversely connected, a reverse current may be blocked to prevent an
occurrence of the reverse current.
[0036] As described above, according to the exemplary embodiments
of the present disclosure, the current supplied from the battery
when the battery is reversely connected may be blocked, to protect
the power switch. According to the present disclosure, components
configuring the power switch may be manufactured by the same
process, the current may be configured to senses without the
correction circuit that corrects process and temperature
deviations, and the current sensing error may be improved. Further,
according to the present disclosure, since a separation element
such as the diode or the FET that prevents the reverse connection
is not additionally required, a voltage drop and power loss due to
an additional element connection may be reduced.
[0037] Hereinabove, although the present disclosure has been
described with reference to exemplary embodiments and the
accompanying drawings, the present disclosure is not limited
thereto, but may be variously modified and altered by those skilled
in the art to which the present disclosure pertains without
departing from the spirit and scope of the present disclosure
claimed in the following claims.
* * * * *